Gastric Ulceration in Tumor-Bearing Rats

Summary

Sprague-Dawley rats, in which the Walker carcinosarcoma 256 (1 of 2 lines) was transplanted, were fed ad libitum one of several diets (casein base, dried tumor base, chow, diluted evaporated milk), or were fed a restricted amount of the casein diet. These rats were examined for gastric ulcers. Normal (non-tumor-bearing) rats were fed ad libitum or were partially or totally deprived of food. In tumor-bearing rats fed ad libitum, ulcers developed in both the forestomach and in the glandular area of the stomach 21 or more days after tumor transplant with all diets fed except chow. Ulcer incidence increased with age of the tumor, but variability was great. In tumor-bearing rats partially deprived of food and killed 18 days after transplant, the ulcer incidence was significantly lower than in rats with spontaneous comparable intake killed 28 days after transplant. In normal rats totally deprived of food, the incidence of forestomach ulcers increased with the period of deprivation (3–7 days); glandular ulcers developed only after more than 6 days of deprivation. From the relation of ulcer incidence to tumor weight, food intake, carcass weight change, and adrenal weight, it appears that gastric ulceration in the tumor bearer requires a degree of food deficit, such as occurs with progressive tumor growth, in conjunction with some minimal stage of tumor development. No definitive cause for the ulceration has been found.